• Ubuntu 16.04 (kernel version 4.19)
• ftrace open

• kernel

current kernel version is 4.19 (selfbuild) if you want to use in other version,just do some porting job.

and kernel-headers is needed.

• python numpy library

NumPy is the fundamental package for scientific computing with Python.

# install pip tool in you server
apt-get install python-pip

# install numpy library 
pip install numpy

• run the python script run.py

Following is a example

# insert the module, set the sample ratio 0.01
./run.py start -s 0.01

# collect the data for 20 second, and analysis the data . (the port we interest is 11211) 
./run.py deal -t 20 -p 11211

# remove the module
./run.py stop							

• how to change probe pront?

change the file config.json, the format is like this

{
	"name" : "function_name",
	"type" : x,   # type of the function, detail you can read the wiki
	"skb" : x,    # parameter position of skb, 
	"sk" : x,     # parameter position of sk,
	"mask" : x    # 0 means not probe , 1 means probe
}

• why no output

Situation 1, you just shutdown the ftrace, you should keep the ftrace open. You can do this by setting /proc/sys/kernel/ftrace_enabled and /sys/kernel/debug/tracing/tracing_on to 1

Situation 2, you set a too low sample ratio or your load program have too less network communication.

• NOT support probe reenter

You should not kprobe/ftrace the same function in this tool, or something weird may happen!!(maybe you need to reboot to set everything ok)